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Biomedical subjects

L H Olsen

Publications and source records attributed to L H Olsen.

At least 19 recordsLinked to original sources
PubMed2005

Body size, but neither age nor asymptomatic mitral regurgitation, influences plasma concentrations of dimethylarginines in dogs.

Asymmetric dimethylarginine (ADMA) is a marker of various cardiovascular diseases in man. The aim of the present study was to test if Cavalier King Charles Spaniels (CKCS) with varying degrees of mitral regurgitation (MR) had increased plasma concentration of ADMA and furthermore, characterize the plasma level of ADMA and symmetric dimethylarginine (SDMA) in normal dogs. Seventy-six dogs were included (44 CKCS and 32 dogs of other breeds). The CKCS had various degrees of MR, whereas the remaining dogs had either no or minimal MR. Apart from cardiac murmurs, no dogs showed signs of cardiac or systematic disease. The degree of MR had no significant influence on ADMA (P = 0.33). Body weight was directly associated with ADMA (P = 0.0004) and creatinine was directly associated with SDMA (P<0.0001). Furthermore, the plasma concentration of ADMA was three to four times higher than found in healthy humans.

Age Factors↗
PubMed2004

Determinants of weak femoral artery pulse in dogs with mitral valve prolapse.

In three substudies encompassing 247 dogs from two breeds predisposed to myxomatous mitral valve disease (MMVD), femoral artery pulse strength was palpated and related to potential explanatory factors, including quantitative echocardiographic measures of MMVD, aortic and femoral artery diameter and wall thickness and blood pressure. In addition, in 109 Cavalier King Charles Spaniels (of which 61 were included in the three substudies mentioned above), the relation between femoral artery pulse strength and presence of thrombocytopenia was investigated. In 26% of the dogs, a pulse </=50% of normal strength was detected; six dogs (2.0%) had an absent pulse unilaterally or bilaterally. Mitral valve prolapse severity, degree of obesity, heart rate and age all influenced femoral artery pulse strength negatively. Weak femoral artery pulses were not related to clinical signs or to decreased pulse pressure or stroke volume. A weak femoral artery pulse reflected reduced artery diameter and/or distension rather than occlusion. In conclusion, weak femoral artery pulses in dogs with MMVD seem to be associated with regional/local reductions in blood flow and not arteriosclerosis or platelet count.

Animals↗
PubMed2004

Male fetal pig lower urinary tract function. Part II: free voiding pattern close to term and in the newborn.

PURPOSE: We assessed the development of natural voiding function late in gestation and in the immediate postnatal period in a porcine model. MATERIALS AND METHODS: The study comprised 7 male fetal minipigs (median age 94 days, 0.88 gestation) and 7 male newborn pigs. In all pigs an ultrasonic probe was placed around the subcutaneous urethra and pressure catheters were placed in the bladder and rectum and in the amnionic cavity in the fetal pigs. The catheters were connected to pressure transducers as the flow probe was connected to a flow meter, and the recordings were sampled at a rate of 10 Hz on a personal computer. RESULTS: The newborns had a median voiding frequency of 3.3 times per hour while the fetuses voided a median of 5.9 times per hour (p = 0.16). Both groups voided with a staccato flow at a frequency of 1 to 2 Hz, indicating voiding dyscoordination between the detrusor and urethra. Maximum flow rate increased from median 4.4 ml per minute (range 2.0 to 8.8) in the fetal group to median 10.9 (5.4 to 18.3) in the newborns (p = 0.07). While the minimum opening pressure remained unchanged (median 7.0 cm H2O, range 5.7 to 13.0) vs median 7.6, (range 7.7 to 14.0, p = 0.57) the detrusor pressure at maximum flow decreased from median 22.4 cm H2O (range 16.6 to 39.0) in the fetal pigs to 12.1 cm H2O (8.3 to 22.3) in the newborns. CONCLUSIONS: Fetal and newborn pigs have dyscordinated voiding with a staccato flow. While the urethral opening pressure appears to be unchanged, the detrusor pressure at maximum flow decreases during the last period of gestation, indicating decreased urethral resistance. These findings are in accordance with observations made in human infants.

Animals↗
PubMed2004

Computer assisted pyeloplasty in children: the retroperitoneal approach.

PURPOSE: We describe the first series of computer assisted retroperitoneoscopic pyeloplasty in children using the Da Vinci Surgical System (Intuitive Surgical, Inc., Mountainview, California) with regard to setup, method, operation time, complications and preliminary outcome. The small space in the retroperitoneum of children and larger instruments of the computer assisted surgical system make modification of the retroperitoneal access necessary. MATERIALS AND METHODS: In 13 children with a median age of 6.7 years (range 3.5 to 16.2) and ureteropelvic junction obstruction 15 pyeloplasties were performed with the Da Vinci Surgical System. With the patient in a lateral semiprone position the retroperitoneal space was developed by blunt and balloon dissection. Three ports were placed for the computer assisted system and 1 for assistance. Pyeloplasty was performed with the mounted system placed behind the patient. RESULTS: The procedures were completed in all patients with the computer assisted system. Median operative time was 173 minutes (range 76 to 215) and there were no perioperative complications. Median postoperative hospital stay was 2 days (range 1 to 3). Two patients had postoperative complications related to the Double-J catheter (Cook Urological Inc., Spencer, Indiana). In 1 patient the catheter was displaced with its lower end in the distal ureter, and the other patient was rehospitalized with occlusion of the catheter and treated with nephrostomy for a few days. All patients had a satisfying outcome during the preliminary followup period of 1 to 7 months. CONCLUSIONS: In this the first series of computer-assisted retroperitoneal pyeloplasty in children the method seems feasible with shorter operative time and similar complications as in standard retroperitoneoscopic procedures but easier handling of the instruments and shorter training for the surgeon. The costs for the system are still high and only longer followup will reveal whether the more precise placement of sutures and the advantage of the magnified 3-dimensional view lead to at least the same results as the open procedure.

Adolescent↗
PubMed2003

Early echocardiographic predictors of myxomatous mitral valve disease in dachshunds.

Myxomatous mitral valve disease in dogs is heritable, and it is therefore important to detect the early signs of the disease. This study was conducted to assess the predictive value of early echocardiographic and auscultatory signs of mitral valve prolapse, measured in terms of the leaflet thickness, the area of the regurgitant jet, and the intensity of the murmur, on the increases in left ventricular end diastolic diameter (LVEDD) and left atrial diameter (LAD) in a population of 190 clinically healthy dachshunds followed up for three years. The most significant predictor of an increase in LVEDD was the interaction between the index of mitral valve prolapse and the area of the regurgitant jet (P < 0.0001). In dogs with a jet area greater than 50 per cent of the left atrium, the disease progressed more quickly in terms of increases in LVEDD in relation to the severity of the prolapse at the initial examination. In dogs with smaller jets, the initial prolapse index was not significantly associated with increases in LVEDD. The initial index of mitral valve prolapse, the area of the jet and the intensity of the heart murmur were all significant predictors of an increase in LAD.

Animals↗
PubMed2003

Renal function may not be restored when using decreasing differential function as the criterion for surgery in unilateral hydronephrosis.

OBJECTIVE: To evaluate the use of decreasing differential function (DF) as an indication for surgery in children with congenital hydronephrosis followed according to a flow chart with repeated renography and ultrasonography. PATIENTS AND METHODS: The hospital records of consecutive children (0-12 years old) who underwent an Anderson-Hynes pyeloplasty between 1993 and 2000 were reviewed. Follow-up was recommended according to a flow chart, with isotope renography and ultrasonography at 1, 3 and 6 months, and at 1 (2), 3 and 5 years of age. The diagnosis and follow-up were often at the referring hospital. The criteria for surgery included a decrease in renographic DF of > 10% of DF, and a DF of < 42%, breakthrough pyelonephritis despite antibiotic prophylaxis, pain or an anterior-posterior pelvic diameter of > 50 mm. RESULTS: Fifty-two children with unilateral hydronephrosis were included; eight had surgery because of decreasing DF of the hydronephrotic kidney. Seven children had a prenatal diagnosis. Only one of these eight children was managed according to the recommended procedures for follow-up. In two and possibly three children there was significant irreversible kidney damage since the initial renography before surgery. In one child the initial renography was at 15 months and the DF was < 10%. There was a functional improvement after surgery in three children. CONCLUSION: Few children undergo surgery for decreasing DF of the hydronephrotic kidney in this study. Failure to adhere to the follow-up schedule was common; this may jeopardize kidney function when using decreasing DF as a criterion for surgery. Therefore, not complying (by medical staff or the patient) with the follow-up should be considered when using expectant management for asymptomatic hydronephrosis. The serious consequences for renal function of not complying with follow-up can be avoided by surgery if the patient risks renal functional deterioration, by close cooperation with medical staff at referring hospitals, and by close follow-up at an early age with renography and ultrasonography.

Child↗
PubMed2001

Male fetal pig lower urinary tract function in mid second and early third trimester of gestation.

PURPOSE: Routine use of ultrasound during pregnancy has emphasized the need for greater knowledge about normal and abnormal voiding function during fetal live. We describe the developmental changes in lower urinary tract function from the middle of the second to the early third trimester of gestation. MATERIALS AND METHODS: The study included 22 male fetal pigs of 13 pregnant Goettingen minipigs (gestational period 111 to 115 days) with 11 fetuses in the middle of the second (median 61.5 days, 0.55 of term) and 11 fetuses in the beginning of the third trimester of gestation (median 80 days, 0.72 of term). With the sow under isoflurane anesthesia catheters were placed in the bladder, rectum and amniotic cavity of the fetuses, and a flow probe was placed around the distal urethra. After the sow was at light sleep urethral flow, amniotic pressure, abdominal pressure and bladder pressure were recorded a median of 241 minutes. RESULTS: The recordings of 14 fetuses were evaluable. In the middle of the second trimester the fetuses showed an almost constant dribbling with a median flow of 0.2 ml. per minute and a median of 4 concomitant bladder contractions per minute of median 3.5 cm. H2O (detrusor pressure). At the beginning of the third trimester the fetuses had periods of staccato flow (median 0.2 ml. per minute, staccato frequency 1 to 2 Hz.) on top of contractions (median 4 contractions per minute, median detrusor pressure 5.5 cm. H2O) with no flow between voidings. CONCLUSIONS: Development of storage and voiding function in male pigs occurs between the mid-second and early third trimester of gestation, together with emergence of striated sphincter bursting activity, which interrupts flow in the urethra during the voiding phase.

Animals↗
PubMed1999

Neuroendocrine changes in Dachshunds with mitral valve prolapse examined under different study conditions.

Neuroendocrine changes associated with canine mitral valve prolapse (MVP) were studied in 159 Dachshunds older than two years. In study 1, 102 dogs were sampled without controlling diet or fasting period. In good accordance with human findings, the MVP severity correlated positively with plasma renin activity and tended to correlate negatively with plasma aldosterone. These findings were not attributable to any coexistent mitral regurgitation (MR). In study 2, in which diet and fasting period were controlled, 57 Dachshunds younger than seven years were sampled twice through an i.v. cannula: once after approximately 15 minutes in lateral recumbency and again after 10 minutes of walking. In both study 2 settings, neither MVP nor MR correlated significantly with plasma levels of renin, aldosterone, angiotensin-converting enzyme, norepinephrine, epinephrine, or cortisol. We conclude that the increased renin release found in early canine mitral disease is not reproducible under all study conditions, and that it correlates with the severity of MVP and not of MR.

Aldosterone↗
PubMed1998

[Prolonging of the follow-up intervals for non-invasive bladder tumors].

Traditionally, patients with non-invasive bladder tumours are evaluated every three months in the first year(s) after primary resection. In a randomised controlled design we evaluated the consequences of doubling the follow-up intervals for patients with non-invasive bladder tumours (Ta) grade I and II without concomitant urothelial dysplasia. The patients were allocated to one of the two regimens: Regimen I: follow-up every three months for the first two years, every sixth month in the third year and thereafter once a year. Regimen II: every sixth month the first year, and once a year thereafter. Follow-up examinations were usually performed by transabdominal ultrasound, but cystoscopy was performed once a year in all patients. Of the 97 evaluable patients, three patients in regimen I and one patient in regimen II progressed in relation to stage and/or grade in the study period. No patient died from the tumour disease. There was no difference with regard to recurrence and progression between the two groups.

Aged↗
PubMed1995

Breed differences in the plasma renin activity and plasma aldosterone concentration of dogs.

Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were studied in 90 clinically healthy dogs: 15 Beagles, 15 Cavalier King Charles spaniels (CKCS), 15 Medium Sized Poodles, 15 Labrador retrievers, 15 Irish wolfhounds and 15 Newfoundlands. All dogs were fed a low sodium diet for at least 3 days before blood sampling in a home setting. There was a significant difference between breeds with respect to both PRA (P = 0.0002), PAC (P = 0.002) and PRA/PAC ratio (P < 0.0001). The highest PRA values were found in CKCS and Poodles, two breeds known to be predisposed to chronic valvular disease. Five CKCS had PRA values exceeding 3.0 ng/ml/h while this was the case in only one of the remaining 75 dogs. In contrast to the high PRA values, CKCS had low PAC values, and therefore much higher PRA/PAC ratios than the other breeds. In Irish wolfhounds, both the PRA and PAC values were low. In conclusion, considerable breed differences in PRA and PAC were found in the present study. Further studies are needed to determine if there is an association between developing chronic valvular disease and a high PRA in dogs.

Aldosterone↗
PubMed1995

Prolonging follow-up intervals for non-invasive bladder tumors: a randomized controlled trial.

Considerable resources are devoted to the follow-up of patients with superficial bladder tumors. Traditionally these patients are evaluated every three months in the first year(s) after the primary resection. In a randomised controlled design we evaluated the consequences of doubling the follow-up intervals for patients with non-invasive bladder tumors (Ta) with none of the following risk factors: concomitant urothelial dysplasia, tumor grade > II, early recurrence. The patients were allocated to one of two follow-up regimens: Regimen I: follow-up every three months for the first two years and every six months in the third year, thereafter once a year. Regimen II: Every six months for the first year and once a year thereafter. At most of the follow-up visits the bladder was examined by transabdominal ultrasound. Cystoscopy was performed in all patients once a year. The data from the 97 patients were evaluable. Three patients in regimen I and 1 patient in regimen II progressed in grade and/or stage in the observed period. No patient died of his tumor disease. There was no difference with regard to recurrence, progression and tumor-related death between the two groups. The total number of follow-up visits in regimen II was reduced by 37.5% (P = 0.0016) compared to regimen I. The number of patients specific follow-up visits with a recurrent tumor present was increased by 65% (P = 0.0475). In the future we will follow this selected group of patients with non-invasive bladder tumors as described.

Aged↗
PubMed1993

The reliability of staging and grading of bladder tumours. Impact of misinformation on the pathologist's diagnosis.

The influence of misinformation on the reliability of the histopathological classification of bladder tumours was analysed. Four consultant pathologists assessed 40 biopsy specimens of bladder tumours staging invasion and grading the specimens according to the Bergkvist classification. A random sample of 20 specimens was accompanied by systematically distorted information ("bias"-unknown to the pathologists) about previous histological grading of the patient (bias group); the other 20 specimens were used as control group (non bias group). After 6 months a second round with the same specimens was arranged to assess the influence of bias on the intraobserver variation. Using kappa (kappa) statistics the chance corrected interobserver agreement rate was poor both in staging of invasion and grading according to the Bergkvist classification (kappa < 0.50). The kappa values in the intraobserver study ranged from poor to excellent with a tendency towards lower kappa when the observer had been biased. The kappa values in the assessment of malignancy were acceptable to excellent. False information did not affect the pathologists' diagnosis significantly.

Biopsy↗
PubMed1992

Management of the non-descended testis: doubtful value of luteinizing-hormone-releasing-hormone (LHRH). A double-blind, placebo-controlled multicentre study.

In a double-blind, placebo-controlled multicentre study, the effect of luteinizing-hormone-releasing-hormone (LHRH) in 141 boys was analysed after 4-week treatment period with 0.4 mg LHRH nasal spray or placebo nasal spray three times daily. Data from 123 boys was analysed, with 62 boys in the treatment group and 61 in the placebo group. Full response i.e. the testis at the bottom of the scrotum on both sides in boys with bilaterally undescended testes, was found in six patients, one of them in the placebo group [Therapeutic gain of LHRH with 95% CI: 8.1% (0.1-16.6%, P = 0.12)]. Only in these boys could surgery be avoided. Considering the number of testes (and not the number of boys) a significant effect was found on at least one testis in 25% of boys with bilaterally undescended testes [Therapeutic gain with 95% CI: 24.0% (13.2-34.8%, P = 0.001)]. In unilateral undescended testes, the LHRH treatment showed no effect (P = 1.00). The inclusion of retractile testes did not affect our results. In our opinion LHRH has a limited place in treatment of the non-descended testis.

Administration, Inhalation↗
PubMed1991

Stools containing altered blood-plasma urea: creatinine ratio as a simple test for the source of bleeding.

The plasma urea:creatinine ratio (U:C ratio) is known to be elevated in cases of upper gastrointestinal bleeding. Almost all patients with haematemesis have upper gastrointestinal (or generalized) bleeding so that in this study we characterized the diagnostic power of the U:C ratio in patients with stools containing altered blood without haematemesis in the hope that this simple laboratory test (used in conjunction, perhaps, with clinical data) might reduce the number of patients subjected to an unrewarding gastroscopy or colonoscopy. Of 76 cases seen in a provincial and a metropolitan hospital, 42 and 34 patients had upper and lower gastrointestinal bleeding, respectively. Fifty-four per cent of those with upper gastrointestinal bleeding and none of those with lower gastrointestinal bleeding had U:C ratios above 110 on admission. However, a discriminating level of 90 is considered to be more suitable, judged by the quadratic uncertainty score. At this level the odds for upper gastrointestinal bleeding were 15:1.

Aged↗
PubMed1991

Observer variation in the radiographic classification of ankle fractures.

We recorded inter- and intra-observer variations in the classification of ankle fractures by the Lauge Hansen and Weber systems. Radiographs of 94 patients were classified independently by four observers. The observer variation was calculated by kappa statistics, which corrects the obtained values for the agreement expected by chance. There was an acceptable level of agreement for the overall classification into both systems. For the staging of supination-adduction and supination-eversion fractures in the Lauge Hansen system the agreement was poor. The results indicate that future classification systems should be subject to reliability analysis before they are accepted.

Ankle Injuries↗
PubMed1989

Inter-observer variation in assessment of undescended testis. Analysis of kappa statistics as a coefficient of reliability.

In a prospective study the inter-observer variation in the diagnosis of undescended testis was analysed. Two physicians assessed independently the position and motility of the testes of 37 boys referred for undescended testis. The boys were examined in the supine and squatting positions. The observed agreement rate between the observers was 0.90 to 0.97. Using kappa (kappa) statistics, the values were adjusted for the expected chance agreement; kappa values between 0.47 and 0.81 were obtained, slightly higher values for patients in the supine position. Complete agreement on all observations was reached in 13.5% of the patients. Inter-observer variation may be a substantial source of bias in diagnosing the undescended testis and one of the reasons for the varying results in studies of hormonal treatment of this condition. It is also a fact that the number of orchiopexies in some countries exceeds the incidence of this condition.

Child↗